This invention relates generally to decorative moldings and is specifically concerned with decorative trim moldings which may be used as body moldings in automotive vehicles.
Decorative trim moldings are applied to vehicle bodies for the purpose of enhancing the appearance of the vehicle. They may be applied to the body sheet metal not only for appearance purposes but also for protective purposes as well. One type of molding used on vehicle bodies is referred to as a body side molding. It is applied to the sides of the vehicle's body, such as the fenders, doors, and/or quarter panels.
In the past such trim moldings have been made from various materials. For example, early usage involved bright metal, such as chrome plated steel. These moldings were fastened to the body by means of conventional fasteners such as metal clips, screws and the like. With the increased availability of plastic materials, the usage of plastic trim moldings increased significantly. While plastics are generally lighter in weight than their metal counterparts and while they may have in the past been less expensive than metal moldings, plastics possess certain undesirable characteristics. For example, plastic is subject to cracking or chipping and is not nearly as strong or durable as a metal molding. While procedures such as sputtering can be used to impart a metallic looking appearance to a piece of plastic, the appearance is certainly not that of a true bright metal piece. Furthermore the very dramatic increase in the price of raw plastic over recent years has made plastic molding pieces considerably more expensive than they once were.
In general, plastic body side moldings must have a solid cross section of plastic. If attempts are made to reduce the amount of plastic used for a given outward appearance, then the part either becomes weaker or additional complications are introduced into the fabrication of the parts.
In attempts to reduce manufacturing costs while improving upon product quality automobile manufacturers have attempted to use plastic body side moldings which are mounted on a vehicle simply through the use of adhesive cement. In other words there are no separate mechanical fasteners which used to mount the molding to the body metal. These attempts have not been completely successful. One of the problems which is encountered involves curvature and/or irregularities in the vehicle body contour. In order for a plastic molding to have any chance of being successfully applied to the side of the body by means of an adhesive cement or glue it is necessary for the mating surfaces of the molding and the body to be in close conformity. In actual practice this is a very difficult task to achieve on a mass production basis. The adhesive attachment technique is limited by the characteristics of the available adhesives and cements. Generally an adhesive or cement processes only a certain amount of holding force per unit area. In order to provide an adquate surface area between the molding and the body it often becomes necessary for the molding to be made larger in cross sectional area because of the limitations of the adhesive or cement. This means that the molding must be larger in width than might other wise be desired and it also can mean that additional material has to be used in the cross section.
The use of mechanical fasteners is considered less desirable for the reason that it involves the punching of holes in the body members and it increases the number of parts involved as well as the labor required to assemble the fasteners to each hole. Hence although the mechanical fastening technique is acceptable in many instances, it is certainly not as desirable a procedure.
A still further problem with the adhesive fastening technique occurs over the life of the vehicle. Vehicles are subjected to road shock and vibration which impart vibration and distortion to the sheet metal. There are also imparted to the attachment between the trim element and the body and tend to weaken the attachment. Hence in the case of adhesive fastening, these factors can lead to premature separation of the trim piece from the body. A still further problem involves environmental considerations. In the warmer climates such as Los Angeles and the Southern California basin, the exposure to prolonged heat, salt air, high humidity, ozone and ultra-violet radiation tends to attack the adhesives presently known to the industry. The washing of a vehicle with extremely hot water such as used in an auto wash rack and the use of steam in the vicinity, such as is applied to the cleaning of the wheels and wheel wells, can attack the adhesives, intruding between the edge of the molding and the body of the vehicle. While these factors may not immediately cause separation of the trim moldings from the vehicle, they can lead to premature separation. Even in the colder climates problems can occur. For example, water may collect on the top edge of a molding and intrude between the molding and the body. The freezing, thawing, and refreezing can lead to premature separation of the molding from the body. Furthermore the use of road salts, as in Michigan and other regions of the country, can attack the adhesive causing premature separation.
It is further often desired for moldings to be more than simply a metal piece having a strictly metallic appearance throughout its exposed exterior. As examples, it may be desired for moldings to have borders or particular geometrical configurations. These can lead to more complicated fabrication procedure for a molding.
Where metal is used in a molding, there is the potential for electrochemical corrosive action to be initiated if the molding and body metals are dissimilar and come into contact.
The present invention is directed to a new and improved molding which is well suited for use as a trim molding on vehicles bodies such as a body side molding. The present invention overcomes the disadvantages of prior moldings referred to above. One important advantage of the invention is that it is primarily a metallic molding thereby exibiting the desirable strength characteristics of metal moldings; yet at the same time the molding is insulated from the sheet metal body of the vehicle so that problems relating to the use of metal moldings are avoided. Another advantage is that the invention may be practiced in a wide variety of cross-sectional shapes thereby providing a myriad of different appearances for edge moldings; yet, it spite of this versatility, the cross-sectional area and hence amount of material in the cross-section can be minimized while, the outward appearance of the molding would suggest a much more substantial amount of material in the cross-section. The invention also enhances the appearance of a molding without complicating the fabrication procedure because inherent decorative features are imparted to the molding through the manufacturing process. Hence extra manufacturing procedures to include the additional complementary appearance features are not essential. Moreover, the molding of the invention may be attached to the body through any of a number of possible installation procedures. For one it is possible to use adhesives or cements. The invention is more readily conformable to contours and irregularities in the vehicle body and thus better suited for adhesive attachment. Alternative procedures may be used by inclusion of separate adhesive fastening strips; for example adhesive-backed foam or tape, and mechanical plastic fasteners may also be used with certain configurations of the molding. The molding need not have a metallic looking appearance and it is contemplated that various materials may be laminated to the exterior of the molding so as to provide other than metalic appearance if desired. When this is done, less expensive grades of metal may be used thereby minimizing the cost to the consumer.
The body side molding of the present invention comprises a strip of metal to one side of which is applied a layer of insulating material. In the finished molding this insulating material is disposed over the obverse side of the molding so as to insulate the metal of the molding from the vehicle body. The longitudinal edges of the molding are provided with stiffening beads by turning the marginal longitudinal edges over onto the face, or exterior, of the molding. By making the insulating layer cover the full width of the obverse side of the metal strip, the formation of the stiffening beads results in decorative bands of insulation appearing on the exterior face of the molding running along the longitudinal edges. The beads are set inwardly from the rest of the main body of the molding and it is along these inset marginal edges where the attachment of the molding to the vehicle body may take place. For example adhesive may be applied to the obverse side of beads to attach the molding to the vehicle body. Because these edges are spaced apart and because the main body of the molding is outwardly offset relative to the beads a better conformity of the molding to the body can take place. By setting the main body of the molding outwardly, a more substantial outward appearance is also presented to an observer yet the interior of the molding when mounted on a body is essentially a dead air space. Hence, it will be recognized that a lesser amount of material is required in the cross section.
The particular manner in which the beads are formed is susceptible to a number of possibilities. For example, one way to form the beads is by a single 180.degree. reversal of the marginal edges. Alternatively a multiple number of reversals may be employed to build up the thickness of the molding at the beads. Furthermore the reversals may have different orientations depending upon the particular shape of the molding. For one the reversals to form the beads can be made at the ends of inwardly turned flanges which are formed in the main body of the molding. The head of a fastener, preferably plastic, can be lodged in the interior of the molding with diametrically opposite sides of the head of the fastener engaging the respective flanges to retain the molding on the vehicle body with the shanks of the fasteners passing through suitable apertures in the sheet metal body panels. The degree of visibility of the beads will also be a function of the particular construction. In some moldings the beads may be highly prominent while in others, less prominent. These various possibilities contribute to the versatility of the invention as far as being suitable for various molding configurations. The molding is fabricated by conventional roll forming techniques after the insulating layer has been applied to the metal. Where a metallic exterior appearance is not desired, fabrication can be done by laminating a further layer of material to the face of the strip before roll forming. After roll forming the metal is basically fully enclosed by the two layers. By appropriate selection of colors for the layers, various decorative possibilities occur .